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random_bytes

(PHP 7, PHP 8)

random_bytes — Get cryptographically secure random bytes

Descrizione

random_bytes(int $length): string

Generates a string containing uniformly selected random bytes with the requested length.

As the returned bytes are selected completely randomly, the resulting string is likely to contain unprintable characters or invalid UTF-8 sequences. It may be necessary to encode it before transmission or display.

The randomness generated by this function is suitable for all applications, including the generation of long-term secrets, such as encryption keys.

The sources of randomness in the order of priority are as follows:

Nota: Although this function was added to PHP in PHP 7.0, a » userland implementation is available for PHP 5.2 to 5.6, inclusive.

Elenco dei parametri

length

The length of the random string that should be returned in bytes; must be 1 or greater.

Valori restituiti

A string containing the requested number of cryptographically secure random bytes.

Errori/Eccezioni

Log delle modifiche

Versione Descrizione
8.2.0 In case of a CSPRNG failure, this function will now throw a Random\RandomException. Previously a plain Exception was thrown.

Esempi

Example #1 random_bytes() example

<?php
$bytes = random_bytes(5);
var_dump(bin2hex($bytes));
?>

Il precedente esempio visualizzerà qualcosa simile a:

string(10) "385e33f741"

Vedere anche: